The technology of the present disclosure relates generally to distributed antenna systems (DASs) that support distributing communications services to remote antenna units, and particularly to supporting programmable remote communications service sector areas.
Wireless communication is rapidly growing, with ever-increasing demands for high-speed mobile data communication. As an example, local area wireless services (e.g., so-called “wireless fidelity” or “WiFi” systems) and wide area wireless services are being deployed in many different types of areas (e.g., coffee shops, airports, libraries, etc.). Distributed communications or antenna systems communicate with wireless devices called “clients,” “client devices,” or “wireless client devices,” which must reside within the wireless range or “cell coverage area” in order to communicate with an access point device. Distributed antenna systems are particularly useful to be deployed inside buildings or other indoor environments where client devices may not otherwise be able to effectively receive radio-frequency (RF) signals from a source, such as a base station for example. Example applications where distributed antenna systems can be used to provide or enhance coverage for wireless services include public safety, cellular telephony, wireless local access networks (LANs), location tracking, and medical telemetry inside buildings and over campuses.
One approach to deploying a distributed antenna system involves the use of RF antenna coverage areas, also referred to as “antenna coverage areas.” Antenna coverage areas can be formed by remotely distributed antenna units, also referred to as remote units (RUs). The remote units each contain or are configured to couple to one or more antennas configured to support the desired frequency(ies) or polarization to provide the antenna coverage areas. Antenna coverage areas can have a radius in the range from a few meters up to twenty meters as an example. Combining a number of remote units creates an array of antenna coverage areas. Because the antenna coverage areas each cover small areas, there typically may be only a few users (clients) per antenna coverage area. This arrangement generates a uniform high quality signal enabling high throughput supporting the required capacity for the wireless system users.
As an example, FIG. 1 illustrates distribution of communications services to coverage areas 10(1)-10(N) of a DAS 12, wherein ‘N’ is the number of coverage areas. These communications services can include cellular services, wireless services such as RFID tracking, Wireless Fidelity (WiFi), local area network (LAN), WLAN, and combinations thereof, as examples. The coverage areas 10(1)-10(N) may be remotely located. In this regard, the remote coverage areas 10(1)-10(N) are created by and centered on remote antenna units 14(1)-14(N) connected to a central unit 16 (e.g., a head-end controller or head-end unit). The central unit 16 may be communicatively coupled to a base station 18. In this regard, the central unit 16 receives downlink communications signals 20D from the base station 18 to be distributed to the remote antenna units 14(1)-14(N). The remote antenna units 14(1)-14(N) are configured to receive downlink communications signals 20D from the central unit 16 over a communications medium 22 to be distributed to the respective coverage areas 10(1)-10(N) of the remote antenna units 14(1)-14(N). Each remote antenna unit 14(1)-14(N) may include an RF transmitter/receiver (not shown) and a respective antenna 24(1)-24(N) operably connected to the RF transmitter/receiver to wirelessly distribute the communications services to client devices 26 within their respective coverage areas 10(1)-10(N). The remote antenna units 14(1)-14(N) are also configured to receive uplink communications signals 20U from the client devices 26 in their respective coverage areas 10(1)-10(N) to be distributed to the base station 18. The size of a given coverage area 10(1)-10(N) is determined by the amount of RF power transmitted by the respective remote antenna unit 14(1)-14(N), the receiver sensitivity, antenna gain and the RF environment, as well as by the RF transmitter/receiver sensitivity of the client device 26. Client devices 26 usually have a fixed RF receiver sensitivity, so that the above-mentioned properties of the remote antenna units 14(1)-14(N) mainly determine the size of their respective remote coverage areas 10(1)-10(N).
The DAS 12 in FIG. 1 may also be provided in an indoor environment, as illustrated in FIG. 2. FIG. 2 is a partially schematic cut-away diagram of a building infrastructure 28 employing the DAS 12. The building infrastructure 28 in this embodiment includes a first (ground) floor 30(1), a second floor 30(2), and a third floor 30(3). The floors 30(1)-30(3) are serviced by the central unit 16 to provide the antenna coverage areas 10 in the building infrastructure 28. The central unit 16 is communicatively coupled to the base station 18 to receive downlink communications signals 20D from the base station 18. The central unit 16 is communicatively coupled to the remote antenna units 14 to receive the uplink communications signals 20U from the remote antenna units 14, as previously discussed above. The downlink and uplink communications signals 20D, 20U communicated between the central unit 16 and the remote antenna units 14 are carried over a riser cable 32. The riser cable 32 may be routed through interconnect units (ICUs) 34(1)-34(3) dedicated to each floor 30(1)-30(3) that route the downlink and uplink communications signals 20D, 20U to the remote antenna units 14 and also provide power to the remote antenna units 14 via array cables 36(1)-36(6).
The DAS 12 in FIGS. 1 and 2 has a given capacity. In other words, the DAS 12 is configured to support a given number of client devices 26 and an overall data rate for the downlink and uplink communications signals 20D, 20U. This capacity is based on the capacity of the equipment provided in the DAS 12 and the base station 18. As the popularity of client devices continues to increase, the number of client devices 26 that may need to be supported by the DAS 12 may also increase. Further, as technology progresses, the average data rate demand per client device 26 is also likely to increase. To satisfy these increased capacity demands, the DAS 12 may be configured to provide additional capacity beyond the capacity need when the DAS 12 is initially installed. However, this provides an inefficient use of resources in the DAS 12 that may not be utilized for some time to come. However, if the initial capacity of the DAS 12 is limited to the initial capacity requirements, the equipment in the DAS 12 will need to be upgraded and/or replaced to support additional capacity requirements in the future. Further, the capacity demands in certain remote coverage areas 10 in the DAS 12 may be greater than in other remote coverage areas 10. If the capacity of the DAS 12 is increased to respond to the remote coverage areas 10 with increased capacity requirements, other remote coverage areas 10 that do not require the increased capacity are also provided with increased capacity, which can affect the DAS's 12 ability to provide increased capacity to targeted remote coverage areas 10.
No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinency of any cited documents.